void foo(int a)
	switch (a) {
	case 'h':
		fun1();
		exit(1);
	default:
}

creates a warning "Possible switch case/default not preceded by break or
fallthrough comment".

exit( should be treated like return.

Link: http://lkml.kernel.org/r/20170910154618.25819-1-xypron.glpk@gmx.deSigned-off-by: NHeinrich Schuchardt <xypron.glpk@gmx.de>
Acked-by: NJoe Perches <joe@perches.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>